build(deps): bump actions/cache from 3 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v3...v4)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/main.yaml

@@ -34,17 +34,17 @@ jobs:
           components: rustfmt, clippy
         id: toolchain
       - name: Cache cargo registry
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.cargo/registry
           key: checks-${{ runner.os }}-cargo-registry-trimmed
       - name: Cache cargo git trees
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.cargo/git
           key: checks-${{ runner.os }}-cargo-gits-trimmed
       - name: Cache cargo build
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: target
           key: checks-${{ runner.os }}-cargo-target-dir-${{ steps.toolchain.outputs.rustc_hash }}
@@ -108,17 +108,17 @@ jobs:
           echo "::set-env name=LIBGIT2_SYS_USE_PKG_CONFIG::1"
         if: matrix.os == 'windows-latest'
       - name: Cache cargo registry
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.cargo/registry
           key: build-${{ runner.os }}-cargo-registry-trimmed
       - name: Cache cargo git trees
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.cargo/git
           key: build-${{ runner.os }}-cargo-gits-trimmed
       - name: Cache cargo build
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: target
           key: build-${{ runner.os }}-cargo-target-dir-${{ steps.toolchain.outputs.rustc_hash }}